Bicycle trailer hitch

ABSTRACT

A bicycle trailer hitch for securing a trailer to a bicycle, the trailer including a hitch arm and the bicycle having a rear wheel including an axle with an axis of rotation and a frame, the bicycle trailer hitch comprising: a hitch ball including a base end connectable to the trailer hitch arm, an opposite end formed as a ball end and a intermediate portion extending therebetween; and a bicycle-mounted hitch portion mountable on the bicycle and including a socket formed to removably retain the ball end of the hitch ball, the socket including an open end, sized to permit the ball end of the hitch ball to pass therethrough and a retainer end formed to retain the ball end therein, the open end being positioned at the forward end of the socket and the retainer end positioned at the rear of the socket such that the ball end is retained in the retainer end when the hitch arm of the trailer is extending out from the hitch behind the bicycle.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. Ser. No.09/964,884, filed Sep. 28, 2001, pending.

FIELD OF THE INVENTION

[0002] The invention relates to a bicycle trailer and, in particular, toa bicycle trailer hitch for connecting a bicycle trailer to a bicycle.

BACKGROUND OF THE INVENTION

[0003] Bicycle trailers have become quite popular for carrying childrenand cargo. The bicycle trailers are hitched to the rear of the bicycleand towed therebehind.

[0004] Most previous hitches are connectable to the chain stay or toboth the chain stay and the seat stay of the bicycle to retain the hitcharm of the trailer. Recently hitches have been introduced that secureinto the rear axle of the bicycle. One such hitch is described in U.S.Pat. No. 6,099,008 to Caffey.

[0005] Many hitches include complex arrangements for connection betweenthe hitch arm and the hitch. In particular, the connection arrangementsinclude pins that are passed through alignable apertures in the hitcharm and in the bracket that is attached to the bicycle. This procedurecan be frustrating, as the trailer can be difficult to maneuver whengrasping the end of the hitch arm.

[0006] In addition, previous hitches sometimes include complex universaljoint arrangements including many interconnected parts and bearings.This increases the cost of the hitch to consumers.

SUMMARY OF THE INVENTION

[0007] A bicycle trailer hitch according to the present inventionconnects to a bicycle. The hitch securely and effectively hitches atrailer to a bicycle, but is simple to use. The hitch is also economicalto manufacture and therefore can be offered to consumers at low price.

[0008] In accordance with a broad aspect of the present invention, thereis provided a bicycle trailer hitch for securing a trailer to a bicycle,the trailer including a hitch arm and the bicycle having a frame and arear wheel including an axle with an axis of rotation, the bicycletrailer hitch comprising: a hitch ball including a base end connectableto the trailer hitch arm, an opposite end formed as a ball end and anintermediate portion extending therebetween; and a bicycle-mounted hitchportion mountable on the bicycle and including a socket formed toremovably retain the ball end of the hitch ball, the socket including anopen end, sized to permit the ball end of the hitch ball to passtherethrough and a retainer end formed to retain the ball end therein,the open end being positioned at the forward end of the socket and theretainer end positioned at the rear of the socket such that the ball endis retained in the retainer end when the hitch arm of the trailer isextending out from the hitch behind the bicycle.

[0009] The hitch ball base end can be formed to be releasably connected,as by pinning, to the hitch arm. In one embodiment, the base end is aninsert sized to fit into the hollow end of the hitch arm, which isformed of tubing. The base end can alternately, for example, be a cupsized to fit over the outboard end of the hitch arm. A pin, threadedbolt, etc. can be pinned through the insert or cup and the hitch arm.

[0010] The hitch ball base end can be formed integral with the ball end.An intermediate portion extends between the ball end and the base end.The intermediate portion is reduced in diameter relative to the ball endand extends out from the socket while the ball end is retained therein.The intermediate portion can be formed of a resilient material to permitsome flexion between the base end and the ball end.

[0011] The bicycle mounted hitch portion includes a socket for engagingthe hitch ball and is mountable to the bicycle to support the socket onthe bicycle.

[0012] The socket can be formed to closely surround and correspond withthe shape of the ball end of the hitch ball. Alternately, the socket canbe formed to simply retain the ball end therein without consideration asto the shape of the ball head. Of course, when the socket is formed toclosely surround and correspond with the shape of the ball end, thisoffers more even wear between the ball and the socket and morefavourable transfer of forces within the hitch.

[0013] The socket includes an open end, sized to permit the ball end ofthe hitch ball to pass therethrough, and a retainer end. In oneembodiment, the open end includes a closure mechanism, such as forexample a removable pin, a releasable catch or a latchable gate, suchthat the open end can also act to retain the ball end in the socket.Where a pin is used, it can be arranged to fit through the socket andblock the opening, thereby avoiding the problems of having to alignapertures between the hitch ball and the socket. A slot is providedbetween the open end and the retainer end and sized to permit theintermediate portion of the hitch ball to slide therein while the ballis retained in the socket. The slot can be positioned to open at a sideof the socket facing away from the bicycle.

[0014] Applied force, for example of the hitch arm pulling on thebicycle mounted hitch portion can urge the bicycle mounted hitch portionto be dislodged, loosened or to pivot out of its mounted position. Assuch, the retainer end can be arranged on the bicycle-mounted hitchportion such that when the ball end is seated in the retainer end, theball end's axis of rotation within the retainer end is substantiallyaligned, either laterally or vertically, with the bicycle-mounted hitchportion's center of rotation.

[0015] The bicycle mounted hitch portion can include a connector throughwhich it is mountable onto the bicycle. The connector can support thesocket of the bicycle-mounted hitch portion, which can be connected toor formed integral with the connector.

[0016] The connector of the bicycle mounted hitch portion can beselected for connection to any of various parts of the bicycleincluding, for example, one or more of the axle of the rear wheel, theseat post or the frame including for example, the chain stay, the seatstay or the rear wheel drop out. The connector can employ clamping,bolting, strapping, brackets or other connection mechanisms, as desired.Examples of connectors for connecting a hitch to a bicycle are shown, inthe aforementioned patent of Caffey, and in U.S. Pat. No. 5,474,316 ofBritton, U.S. Pat. No. 4,381,117 of French et al., U.S. Pat. No.5,516,131 of Novotny and many others. Many other connectors forconnecting the bicycle-mounted hitch portion to a bicycle will beapparent to a skilled person.

[0017] The connector of the bicycle-mounted hitch portion can, in onembodiment, be mounted between an end of the axle and the frame of thebicycle to which the rear wheel is mounted. The connector can include aplate with an aperture, through which the axle can extend. The plate canbe restrained, as by tight clamping, from pivoting about the axle.Clamping can be provided by a quick release mechanism or by a fastenersecured onto the axle. The plate aperture can extend through the platesuch that, when the bicycle-mounted hitch portion is mounted to theaxle, the plate extends substantially orthogonal to the axle axis ofrotation, with the socket spaced from the aperture. This provides thatthe standard axle securing means, such as a fastener or quick releasemechanism can be clamped against the plate without modifying thestandard axle mounted arrangement of the bicycle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A further, detailed, description of the invention, brieflydescribed above, will follow by reference to the following drawings ofspecific embodiments of the invention. These drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. In the drawings:

[0019]FIG. 1 is a perspective view of a bicycle trailer hitch;

[0020]FIG. 2 is a front elevation view of a bicycle trailer hitch with ahitch ball aligned for entry into the socket and mounted on an axle of abicycle;

[0021]FIG. 3 is a perspective view of a bicycle trailer hitch inventionwith a quick release axle mechanism installed therein;

[0022]FIG. 4 is a side elevation view of a bicycle trailer hitch of FIG.3 mounted on the rear triangle of the bicycle with the hitch ball in thesocket; and,

[0023]FIG. 5 is a front elevation view of the bicycle trailer hitch ofFIG. 2 installed using another means onto an axle of a bicycle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Referring to FIGS. 1 to 4, a bicycle trailer hitch 10 is shown.The bicycle trailer hitch 10 is intended for use in securing a trailer(not shown) having a trailer hitch arm 12 to a bicycle. A trailer, whichincorporates a hitch arm, is shown, for example, in the aforementionedpatent to Britton.

[0025] A bicycle on which the hitch is to be used includes a frame,partially shown at 18, which can have a rear triangle including a pairof horizontal chain stays 20 and a pair of slanted, upwardly extendingseat stays 22. The stays on each side can be joined at the rear of theframe to a rear wheel mounting bracket, termed a “drop-out” 24, whichmounts a rear wheel 26 (partially shown and shown without gearsprockets) to the frame. While a standard bicycle frame is shown, thehitch of the present invention is also useful with other framearrangements, for example, those without chain stays such as rearsuspension bicycles. It is to be understood that while an axle-mountedtype hitch is shown, the bicycle mounted hitch portion can be mounted inother ways to the bicycle for example to the stays of the frame, theseat post, etc. Mounting can be by clamping, strapping, bracketing,bolting etc., as desired. The bicycle-mounted hitch portion can includeconnectors operating on any of these mechanisms.

[0026] For a better understanding of an axle-mounted connector, an axleis illustrated. Rear wheel 26 includes a hub 27 through which a rearaxle 16 extends. Rear axle 16 defines an axis of rotation, indicated at16 x. In the embodiment of FIGS. 1 to 4, rear axle 16 is of thequick-release type. In a quick-release mechanism, axle 16 includes anaxle skewer 28 secured at one end through a quick-release nut 29 and atthe other end through an eccentric lever 30 and a washer 31 againstwhich the eccentric lever bears. The operation of a quick-release axleis well known in the art. In particular, by driving eccentric lever 30to move washer 31 along the skewer the wheel hub and drop-outs 24 areclamped between the quick-release nut and washer 31.

[0027] Hitch 10 includes a bicycle-mounted hitch portion 36 and a hitchball 38. Hitch ball 38 is connectable to the hitch arm of a bicycletrailer. Hitch ball 38 includes a ball end 40, a base end 42 and anintermediate portion 44 extending therebetween. Ball end 40 is generallyspherically shaped and has a diameter d larger than the width ofintermediate portion 44. Base end 42 is selected to be connectable tohitch arm 12. In particular, base end 42 in the illustrated embodimentis shaped and sized to be insertable into the hollow tube which formshitch arm 12. The base end can be shaped and sized to fit closely withinthe hitch arm. An aperture 46 extends through base end 42 and isalignable with a pair of apertures (cannot be seen in the drawings) onhitch arm 12. A fastener such as the illustrated bolt 50 and nut 51 canbe secured through aperture 46 and those apertures on the hitch arm,once they are aligned, to connect the hitch ball to the hitch arm of thetrailer. When installed on a hitch arm, ball end 40 and intermediateportion 44 of the hitch ball extend out from the end of the hitch arm.

[0028] Bicycle-mounted hitch portion 36 in the illustrated embodiment isaxle-mounted and can include a plate 52 with an aperture 54 extendingtherethrough. Plate 52 includes an inner face 56 and an outer face 58.Inner face 56 and outer face 58 are disposed in parallel planes andaperture 54 extends orthogonal to the planes of faces 56 and 58. Whenmounted on a bicycle inner face 56 engages against drop-out 24 andwasher 31 of quick-release mechanism engages against outer face 58 whileaxle 16 extends through aperture 54. Aperture 54 is sized to permit theaxle to pass therethrough and rotate therein. In a preferred embodiment,as shown, a circular indentation 60 is formed on the outer face aboutaperture 54. Circular indentation 60 causes washer 31 and thereby axle16 to be centered relative to aperture 54.

[0029] It can be useful to provide a hitch that works with standard axlearrangements. In the illustrated embodiment, the aperture extendsthrough the plate such that when the bicycle-mounted hitch portion ismounted to the axle, the plate extends substantially orthogonal to theaxle axis of rotation. This provides that the standard axle securingmeans, such as a fastener or the lever 30 and washer 31 of the quickrelease mechanism can be clamped against the plate without modifying thestandard axle mounted arrangement of the bicycle.

[0030] Bicycle-mounted hitch portion 36 also includes a socket 62rigidly connected to plate 52. Socket 62 includes an open end 64 and aretainer end 66. The socket is formed with consideration as to thediameter d of the ball end of hitch ball 38 such that the ball end canfit through open end 64 and seat within retainer end 66. The retainerend is formed to generally support and permit rotation therein of ballend 40, as limited by abutment of intermediate portion 44 against thesocket material. A slot 68 is formed between open end 64 and retainerend 66. Slot 68 is formed to permit movement of hitch ball intermediateportion 44 therealong while blocking passage therethrough of ball end40. In the illustrated embodiment, retainer end 66 is formed at the rearend of the socket. In this way, when trailer is being towed behind thebicycle, ball end 40 is securely seated in retainer end 66. Bicyclemounted hitch portion generally includes an inner facing side, forexample, including inner face 56, which faces the bicycle and slot 68can extend about the side of the socket, opposite inner facing side,such that ball end 40 rotates within the socket mainly about an axis 40x generally perpendicular to the long axis 38 x, extending between theball end and the base end of hitch ball 38. This permits hitch arm torotate laterally and rearwardly outwardly relative to thebicycle-mounted hitch portion 36 when it is mounted on the rear axle ofa bicycle.

[0031] To retain hitch ball 38 within the socket, a closure mechanism isprovided adjacent open end 64. While other closure mechanisms can beused, in the illustrated embodiment of FIG. 1, a pair of alignedapertures 70 is formed adjacent open end 64, which accept and retain apin fastener 72 therein. Pin fastener 72 can include various releasablelocking means for securing within aperture 70. In the illustratedembodiment, pin 72 includes an enlargement such as, for example,enlarged portion 73 (FIG. 1) or ring 75 (FIG. 3), at one end and aspring biased detent ball 74 at the other end. In the embodiment of FIG.3, to prevent loss of pin 72 when the pin is not in use in theapertures, a strap 76 can be secured at its first end to the pin and toanother position, such as to hitch arm 12, at its opposite end.Apertures 70 can be positioned on the socket with consideration of thediameter d of ball end 40 such that when pin 72 is inserted into theapertures, ball end 40 is held closely between pin 72 and the retainerend of socket 62. This reduces rattling noises arising from the ballhead moving within the socket and reduces damage to the ball end and thesocket by vibrational wear.

[0032] In another embodiment illustrated in FIG. 2, the closuremechanism is a closeable gate 78 mounted adjacent the open end. Gate 78is mounted on a hinge, which permits the gate to swing inwardly to allowthe ball end to pass into the socket but which is locked againstswinging outwardly toward the open end unless button 79 is pressed whenpressure is applied outwardly to the gate. Thus, gate 78 locks ball end40 into the socket until released by pressing button 79.

[0033] Bicycle-mounted hitch portion 36 can be formed compact to reduceits effect on the appearance, size, etc. of the bicycle and/or to reduceits tendency to be affected by torque. For example, socket 62 can bepositioned as close as possible to aperture 54 without blocking accessto the aperture and without limiting access to the socket by the hitchball. With consideration to size, torque reduction and ease of use, thesocket can be offset from the aperture and spaced below it, asdetermined by gravity when portion 36 is mounted on the bicycle axle,and the retainer end 66 of the socket can be positioned relative toaperture 54 such that when the ball end of the hitch ball is seated inretainer end 66, axis 40 x of ball end 40 is aligned with aperture 54,which is the center of rotation of the connector.

[0034] Applied force, for example of the hitch arm pulling on thesocket, will urge bicycle-mounted hitch portion 36 to pivot relative toits point of connection on the bicycle. To act against such pivotalmovement, for example in an axle-mounted connector, inner face 56 can beknurled or otherwise roughened to enhance engagement of thebicycle-mounted hitch portion against the drop-out of the bicycleagainst which it is engaged.

[0035] A safety strap 80 can be used in connection with hitch 10 toprevent separation of the trailer from the bicycle in the event that anypart of the hitch should come loose. Strap 80 can be secured to hitcharm 12 by bolt 50 and includes a clip 82 at its loose end for connectionto a D-ring 84 also secured to bolt 50. Strap 80 can be extended aboutchain stay 18, seat stay 20 or the axle and clipped onto D-ring 84 whena trailer is secured to the bicycle.

[0036] It will be appreciated from the foregoing description that hitcharm 12 is free to rotate about axis 40 x through a significant arc.Pitch and roll of the hitch arm relative to socket 62 can be permittedby selecting the thickness of intermediate portion 44 to be less thanthe width of slot 68. Alternately or in addition, intermediate portion44 can be formed of a resilient material permitting some flex betweenball end 40 and base end 42 of the hitch ball. In one embodiment, hitchball 38 is formed entirely of a resilient material such as a polymericmaterial, for example polyurethane, which permits flex in intermediateportion 44. The resilient material can permit some flex in the hitchball, but is not so flexible as to create a sloppy connection betweenthe trailer and the bicycle.

[0037] Bicycle-mounted hitch portion 36 can be formed of variousmaterials, as will be appreciated. In one embodiment, a durable, rigidmaterial, such as for example a polymer or metal, can be used. The useof a castable material, such as an aluminum/zinc alloy, can facilitatemanufacture.

[0038] Bicycle trailer hitch 10 is relatively easy to manufacture andcan be installed on a bicycle and trailer simply and effectively.Attachment of an axle-mounted hitch, for example, can be by aquick-release axle 16 including a skewer 28, eccentric lever 30 andwasher 31, as illustrated in FIGS. 1 to 4. The bicycle-mounted hitchportion and hitch ball can be sold with or without a quick-release axlemechanism. In some applications, the existing quick-release axle on thebicycle can be used to secure the bicycle-mounted hitch portion.Alternately, it may be useful to provide a replacement quick-releaseaxle which includes a skewer selected to have a length to accommodatethe bicycle-mounted hitch portion thereon and a construction towithstand the torque which may be applied to the axle.

[0039] In another axle-mounted embodiment illustrated in FIG. 5, thebicycle-mounted hitch portion of the present invention is mounted to therear axle by a non-quick-release rear wheel mounting. In such a mountingarrangement an axle 90 extends through the hub 27 of the rear wheel andis engaged against the drop-outs 24 of the bicycle by nuts 92. Thebicycle-mounted hitch portion 36 of the present hitch can be used inunmodified form relative to that of FIGS. 1 to 4 with such an axlemounting arrangement. In particular, nut 92 on one side of the axle canbe secured against outer face 58 of the plate 52. Again, socket 62 isprovided adjacent to the aperture in the plate, but does not blockaccess to it or to nut 92.

[0040] As will be appreciated from the foregoing in order to use thetrailer hitch of the present invention, bicycle-mounted hitch portion 36is mounted onto a bicycle and hitch ball 38 is mounted onto a hitch arm12 of a bicycle trailer. In particular, base end 42 of the hitch ball isinserted into the hollow end of hitch arm 12. Aperture 46 of base end 42is aligned with the hitch arm aperture 48 and bolt 50, or otherfastener, is inserted therethrough. Straps 76 and 80 are secured by bolt50.

[0041] To install the illustrated axle-mount version of bicycle-mountedhitch portion 36 of the hitch, it is necessary to remove the originalquick-release mechanism from the rear wheel of the bicycle. This is doneby removing the quick-release nut and associated springs and removingthe skewer from the hub. As noted previously, bicycle-mounted hitchportion 36 can be used with an existing quick-release mechanism or witha quick-release mechanism provided with a selected skewer. In any event,in order to mount the bicycle-mounted hitch portion onto the rear axle,skewer 28 of the axle is inserted through aperture 54 so that outer face58 faces eccentric lever 30. Skewer 28 is then inserted through the hubof the rear wheel and quick-release nut 29 and associated springs aresecured at the end of the skewer and bicycle-mounted hitch portion 36 isdisposed on the lever side of the axle. The rear wheel with axle 16 andbicycle-mounted hitch portion 36 attached is then installed on drop-outs24 of the bicycle frame, such that inner face 56 engages againstdrop-out 24 on the lever side of the quick-release axle. Generally, itis desirable to mount the hitch on the side of the wheel opposite thegear sprockets. However, the hitch can be mounted on the other side ifrequired. Quick-release nut is then adjusted so that eccentric lever canbe clamped down against washer 31 to clamp the wheel onto the drop-outs.If a non-quick release axle is used such as that of FIG. 5, the nuts 92are used to clamp the wheel and the bicycle-mounted hitch portion ontothe bicycle frame.

[0042] If a connector is used that is fixable to another (non-axle) partof the bicycle, that connector can be clamped, fastened, strapped, etc.,in accordance with the operation of the connector, to the bicycle.Again, generally the mount can be out of the way of the chain and gears.

[0043] The bicycle-mounted hitch portion 36 can be mounted so thatsocket 62 is positioned below, with respect to the normal operationalorientation of a bicycle, the connector with open end 64 of the socketfacing toward the front of the bicycle.

[0044] The hitch arm with hitch ball 38 attached is then brought towardsthe socket and inserted into the open end thereof. The ball end is movedinto the socket until it seats against retainer end 66. Pin 72 is theninserted into apertures 70 until detent 74 locks under the socket. Ballend 40 is then captured in the socket. Strap 80 can then be wrappedaround the frame and clip 82 engaged to ring 84. The trailer can, inthis way, be secured to the bicycle and ready for use.

[0045] It will be apparent that many other changes may be made to theillustrative embodiments, while falling within the scope of theinvention and it is intended that all such changes be covered by theclaims appended hereto.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A bicycle trailer hitchfor securing a trailer to a bicycle, the trailer including a hitch armand the bicycle having a frame and a rear wheel including an axle withan axis of rotation, the bicycle trailer hitch comprising: a hitch ballincluding a base end connectable to the trailer hitch arm, an oppositeend formed as a ball end and an intermediate portion extendingtherebetween; and a bicycle-mounted hitch portion mountable on thebicycle and including a socket formed to removably retain the ball endof the hitch ball, the socket including an open end, sized to permit theball end of the hitch ball to pass therethrough and a retainer endformed to retain the ball end therein, the open end being positioned atthe forward end of the socket and the retainer end positioned at therear of the socket such that the ball end is retained in the retainerend when the hitch arm of the trailer is extending out from the hitchbehind the bicycle.
 2. The bicycle trailer hitch of claim 1 wherein theintermediate portion is formed of a resilient material to permit someflexion between the base end and the ball end.
 3. The bicycle trailerhitch of claim 2, wherein the intermediate portion is formed ofpolyurethane.
 4. The bicycle trailer hitch of claim 2, wherein the hitchball is formed of polyurethane.
 5. The bicycle trailer hitch of claim 1,the socket further including a closure mechanism at the open end toclose the open end.
 6. The bicycle trailer hitch of claim 1 wherein thetrailer hitch arm is formed as a tube including a hollow end and whereinthe base end is formed as an insert sized to fit into and be engaged inthe hollow end of the hitch arm.
 7. The bicycle trailer hitch of claim 1wherein the ball end and the base end are aligned along a long axis ofthe hitch ball and the hitch ball is selected to extend out from thehitch arm with its long axis substantially in line with the long axis ofthe hitch arm
 8. The bicycle trailer hitch of claim 1 further comprisinga strap connectable to the hitch ball and extendable to engage about thebicycle.
 9. The bicycle trailer hitch of claim 1 the bicycle-mountedhitch portion including an inner facing side, oriented toward thebicycle when mounted on a bicycle, and the socket further including aslot extending between the open end and the retainer end, the slot beingpositioned at a side of the socket facing outwardly from the innerfacing side and being formed to permit movement of the intermediateportion therealong, while blocking the passage therethrough of the ballend.
 10. The bicycle trailer hitch of claim 9 wherein the slot extendsabout the rear of the socket.
 11. The bicycle trailer hitch of claim 9wherein the slot includes a width larger than the thickness of theintermediate portion.
 12. The bicycle trailer hitch of claim 9, whereinthe retainer end is positioned relative to the bicycle-mounted hitchportion such that when the ball end is seated in the retainer end, theball end's axis of rotation within the retainer end is substantiallyaligned with the bicycle-mounted hitch portion's center of rotation. 13.The bicycle trailer hitch of claim 5, wherein the closure mechanism ispositioned relative to the retainer end to hold the ball end securelybetween the closure mechanism and the retainer end, when the ball end ispositioned in the socket.
 14. The bicycle trailer hitch of claim 5wherein the closure mechanism is a pin and the socket further includespin-retaining holes and the pin-retaining holes are spaced from theretainer end, with consideration as to the ball end's diameter, suchthat the ball end is held closely between the retainer end and the pin,when the ball end is positioned in the retainer end and the pin isextended through its pin-retaining holes.
 15. The bicycle trailer hitchof claim 1, the bicycle-mounted hitch portion further including aconnector supporting the socket and through which the bicycle-mountedhitch portion is mountable to the bicycle.
 16. The bicycle trailer hitchof claim 15 wherein the connector is mountable to the bicycle bybolting.
 17. The bicycle trailer hitch of claim 15 wherein the connectoris clampable to the bicycle.
 18. The bicycle trailer hitch of claim 15wherein the connector is clampable against the bicycle frame.
 19. Thebicycle trailer hitch of claim 1 wherein the connector is a plateincluding an aperture, the plate being mountable on the axle of the rearwheel of the bicycle with the axle extending through and rotatablewithin the aperture.